Freudenberg Battery Lab Design Considered Human, Environmental Safety

To test thermal events and more, lab built to keep employees safe with structural barriers and the outside air clean with an advanced system of scrubbers and filtration.

Engineers observe a thermal event over a monitor at Freudenberg Sealing Technology’s new battery lab. The chemical emissions released by the fire are scrubbed multiple times before being vented outside the building. (Freudenberg)

As more OEMs and suppliers begin developing and manufacturing batteries for EVs, many are discovering the specific needs of a testing program. Namely, dedicated labs that are built to keep researchers and others safe as cells and packs are subjected to extreme testing. Freudenberg Sealing Technologies has answered that need by adding such a facility to existing R&D space at its headquarters in Plymouth, Mich.

Company officials said that everything from the construction of the testing chambers to the level and quality of personal-protection equipment was considered when designing the new lab. (Freudenberg)

They’re realizing what University of Michigan Professor of Mechanical Engineering Anna Stefanopoulou put into words at the 2023 Battery Show North America: “To understand battery engineering, we need to make them, we need to test them and use them. And at the end, you'll need to sort of kill them and learn how actually to protect ourselves. And – actually experience all these phases of the battery life.”

That’s the process Freudenberg Sealing now is prepared for in its new lab, which takes up 1,300 sq-ft (121 sq-m) of floor space and has two 8-ft x 8x-ft x 8-ft battery boxes and a shielded test-control station. The company said in a release that the battery boxes, the inside of which engineers view by camera, were designed by fire and explosives experts to withstand even catastrophic results of thermal runaway events in single cells, modules and battery packs up to 25 kWh. That’s the energy equivalent of a few pounds of TNT. Chad Bauer, senior vice president of technology and innovation, said the company has a long heritage in material development, “Our experience with fire and thermal applications began more than 20 years ago with our aerospace products,” he said.

The room also features 9V, 100-amp low-voltage charging, as well as 800V, 600-amp high-voltage charging. The company said it can now evaluate conditions created by thermal runaways caused by battery punctures, overcharging and overheating – a notable risk for the increasingly high-capacity lithium-ion battery packs in new EVs.

The lab isn’t just safe for its users, it’s built to be safe for the local environment, too. The company said the test chambers have a multi-stage exhaust system that removes toxic gases and particulates before they escape to the outside air. This is done by including a quencher to cool gases and condense particulates, as well as a two-phase scrubber stack topped with charcoal filtration on the roof level.

Heather Shuman, mechanical lab manager for Freudenberg in the Americas, said the company consulted design and construction experts while planning the lab. Steel-reinforced concrete walls are at the back of the lab and explosion pressure vents are integrated in the exhaust system. The test chambers themselves have numerous sensors to monitor pressure, flow and gases. A CO2 fire-suppression system covers the entire lab as a backup to the standard sprinkler system. Power to the entire area is backed up with a standby generator. “We’re working with heat, pressure, gases and fire in this laboratory,” Shuman said, adding that safety protocols will be reviewed regularly. “Battery events are dangerous, but we are equipped so we can conduct this research safely and responsibly.”

Bauer said the company made a multi-million-dollar investment to achieve a goal of reducing development times. “The new lab enables us to conduct testing of different cell chemistries, cell types and battery configurations,” he added.

Freudenberg Sealing Technologies is part of the larger Freudenberg Group.